The present invention relates to a process for the automatic non-contact surface inspection of cylindrical parts and to an apparatus for its realization.
In order to meet the rigid requirements established today in the industry for parts to be mounted, a series of quality assuring measures are needed, including, among others, an inspection of the surface properties of the parts. This inspection is presently carried out visually, that is, for example, the parts are constantly observed by two persons in the course of manufacture on two visual inspection lines arranged parallel to each other. In this manner, the inspectors may manually sort out parts presenting surface defects. During this procedure, both the surface and the contact surface are inspected for any surface damages and for the penetration of foreign particles in the grip of the tool which may handle the parts. In this way, the inspected parts can be mounted with assurance by the ultimate user by automatic assembly methods.
It is disadvantageous in inspections of this kind that reliability exclusively depends on persons, so that a "zero-error requirement" cannot be met due to the heavy psychological stress on the inspection personnel which is due at least in part, to the large number of workpieces to be inspected during this procedure.
It is, therefore, an object of the present invention to provide a process which renders it possible to avoid the disadvantages of the prior art in that an automatic non-contact surface inspection of the cylindrical parts is carried out by a fully automatic, mechanized image processing station.
It shall be possible simultaneously to detect the following kinds of defects:
(a) grooves and scores; PA1 (b) excessively rough surface in general; PA1 (c) radially directed indentations; PA1 (d) striking and blow marks; PA1 (e) incompleteness of surfaces regarding the shaping of edges; PA1 (f) existance/non-existance of foreign matter at inside surfaces of application of force at a front side of a workpiece; and, PA1 (g) differentiation between inevitable or admissible lubricant residues and real defects at the barrel surface.
Another object of the invention is to provide a suitable apparatus for realizing the process.